InterviewBit Problems   NEXTGREATER : Unsolved

About the NEXTGREATER : Unsolved category (1)
Approach ! (Hint: Use stack) (1)
JAva stack solution (1)
How to shape Thought process? (4)
Next Greater Element in O(N) using stack (1)
I solved this in O(n^2) time.......... Is there Any better Solution? (6)
Yes you could solve in O(n) time (1)
I solved it in O(n^2) time and all tests passed! (3)